This chapter focuses on concepts and processes that influence the delivery of psychological services in schools. Posing questions about effectiveness can serve as a valuable heuristic for organizing one’s thoughts about features and dimensions of psychological services. The chapter examines four major conceptual dimensions along which services vary: direct-indirect, centralized-decentralized, proactive-reactive, and rural-urban. It also examines, from a child-as-client perspective, the directness and also focuses on four major psychological services generally provided by school psychologists. These four major psychological services are assessment, consultation, intervention, and research. The chapter also focuses on the development of a generic model of school psychological services that integrates components from both the assessment and the consultation models. It presents the generic service delivery model on some basic assumptions about work with potentially handicapped or troubled individuals. The chapter also presents an overview of the key concepts discussed in this book.